Given that mobile phones have wires and electricity then they are creating small magnetic waves which will impact others. That all said this technolody is very suitable for underwater GPS were a GPS signal does not penetrate the water due to weakness and how bad radio travels thru water in general.

So given that I would have to questions if the military don't already use something very similiar in submarines. Lets say I'd be very supprised if this was not being already utilised in some form or another in that feild.